The present invention relates to a scraping mechanism for planter disks. More particularly, it relates to a rotary scraper for scraping soil collecting on the outside of a double disk planter disk during operation.
In the field of grain planters, a problem encountered with planting grain using a disk-type double disk row planter is that of soil sticking to the disks. A double disk row planter is one in which a pair of rotating disks are mounted in tandem, at an angle, with the leading edge of the disks being angled towards each other. Viewed from the top, the two planter disks form a "V" shaped configuration. As the planter disks rotate, the leading edge of the "V" breaks the soil and pushes it to either side, to form a furrow. Immediately behind the leading edge, a grain tube is positioned to drop grain into the furrow at a predetermined rate. Normally, situated immediately behind the planter disks are a set of press wheels which press the furrow closed and seal the seed within the ground. If soil sticks to the interior or exterior of the disks, it can cause the furrow to become deformed by soil on the exterior of the disks increasing the width of the furrow. The collected soil can also form inside the "V" where it may catch seed dropping from the grain tube and prevent it from falling into the furrow, thus interfering with the seed spacing. Normally the soil collects on the interior of the double disks until either the disks stop turning all together, or it falls out in one large clump, dropping all of the collected seeds with it in one small area. To achieve consistent grain spacing, neither alternative is permissible.
Scrapers have been known in the art which are mounted to clean the planter disks to prevent the soil accumulation problems mentioned above. Also, scrapers have been known in the art of removing soil from plow disks, although the considerations are different in the field of scrapers for plow disks because there are no concerns with the furrow spacing or grain spacing, the only objective being to keep the plow disk turning to break the soil. However, the dirt can collect in the disks to the point where the disks stop turning.
Among the proposals for rectifying the problems relating to planter disks are those disclosed by the patents to David (U.S. Pat. No. 808,021) and Bowerman (U.S. Pat. No. 4,206,817). However, these references did not take into consideration problems relating to the proper size, mounting, shape and placement of the scrapers.
Generally, scrapers are of the wheel type, such as found in the Davis and Bowerman references, or are chisel type, with chisels or points which contact the accumulated dirt to scrape it loose. Chisel type scrapers may perform adequately in some situations, but when the soil being planted is highly compactible, dirt may compact on the planter disks underneath the chisel scraper to the point that the chisel is not able to scrape the dirt off the planter disks and the disks may stop turning. For this reason, it has been recognized that rotary scrapers are preferable, because they are capable of "slicing" the dirt off as they rotate in conjunction with the planter disk.
As stated, placement of the rotary scraper is important to proper operation. The references of Davis and Bowerman disclose rotary scrapers in which the axis of the scraper is on a different vertical plane than the axis of the planter disks. It is also noted that these two references also place the scraper disks on the rear of the planter disks instead of on the front. However, placing the rotary scrapers on the back of the planter disks may cause the dirt to fall into the press wheels and cause them to clog. Applicant has found it more desirable to place the rotary scrapers on the front side of the planters disks so that the dirt accumulated will fall off to the side or fall underneath the planter disks and press wheels, where they will not interfere with proper operation.
When placed on the front of the planter disks, the axis of the scraper disks should be in the same vertical plane as the axis of the planter disk in order to remove the dirt at the point furthest removed from the axle of the planter disk. This is desirable because it enables the rotary scraper to remove dirt at the point where it is least likely to drop into the axle of the planter disk and interfere with its rotation.
Another feature which is desirable on rotary scrapers is that they be located the proper radial distance from the axis of the planter disks. For example, the rotary scrapers disclosed in Bowerman and Davis show the axle of the rotary scraper to be fully inside the circumference of the planter disk. If dirt is accumulating only around the very edge of the planter disk, then this location may pose no significant problems because the rotary scraper can freely rotate. However, if dirt is accumulating several inches in from the edge of the planter disks, this means that the rotary scraper is contacting the accumulated dirt over substantially its entire diameter. When contact of this type occurs, the forces which cause the rotary scraper to rotate (i.e. contact of the rotary scraper along only its edge) cease to occur, and the rotary scraper will come to a stand still and merely act as a solid scraper, removing the dirt from the planter disk without rotating.
If the rotary scraper is positioned so that the scraper axle aligns with the edge of the planter disks, so that approximately half of the rotary scraper protrudes outside the edge of the planter disk, then it will be insured that the scraper will rotate regardless of the width of the band of dirt which is accumulated on the planter disks because the scraper will contact dirt along only 1/2 of its circumference, at most, and this friction will cause the scraper to rotate.
A final consideration in the placement of rotary scrapers is the means of mounting them to the planter frame. Both Davis and Bowerman disclose spring loaded scrapers. However, in particularly hard compacting soil, the spring tension may allow soils to build up underneath the scraper as the spring gives way. In some instances, this can cause the planter disk to stop turning. Therefore, Applicant has found it desirable to mount the scraping means rigidly to the planter frame.
Further, in providing a rotary scraper for planter disks, it is desired that the scraper be designed as an attachment which can easily be added to most standard models of planters.
Therefore, it is an object of the present invention to remove soil from the disks of a planter while the disks are in motion to allow for proper operation of the planter.
Further, it is an object of the present invention that this removal of soil be done simply and effectively.
Further, it is an object of the present invention to provide a scraper adaptable to be added to most types of planters.
Other objects of the present invention are evident, or will become so, during the description of the preferred embodiment, which follows.